迭代数组的问题

Question

我在浏览json文件中的数组数据时遇到问题。

这是我的代码

$barcode = '0000000' //just an example this is set as a variable

$json_data = json_decode($json,true); 

foreach ($json_data as $data){
    $barcodejson = $data['Barcode'];

    if($barcodejson == $barcode){
        $alreadyscanned = 'This user is already in your contacts';  
    } else { do something}
}

我遇到的问题是它只是“查看”最后一组数据而不是全部数据。如果我把条形码放两次我得到错误This user is already in your contacts但如果我把一个新的，然后现有的条形码再次它不起作用。

我确定它与foreach循环有关，但无法弄明白。

我的json数据结构如下：

[
{
    "FirstName": "lee",
    "LastName": "skelding",
    "Email": "mail.mail.com",
    "Barcode": "732580652913857773001",
    "Phone": "00000000",
    "Company": "SKELLATECH V3",
    "Position": "CEO"
},
{
    "FirstName": "Kenneth",
    "LastName": "Brandon",
    "Email": "mail.mail.com",
    "Barcode": "732559813913833509001",
    "Phone": null,
    "Company": null,
    "Position": null
},
{
    "FirstName": "lee",
    "LastName": "skelding",
    "Email": "mail.mail.com",
    "Barcode": "732580652913857773001",
    "Phone": "0000000000",
    "Company": "SKELLATECH V3",
    "Position": "CEO"
}
]

我想要做的是查看json文件中是否已存在条形码编号，如果它确实显示错误，如果它没有继续我的其余代码并添加新数据

Answer 1

对于第二次迭代，$alreadyscanned将设置在与该条件不匹配的用户上（如果已扫描的用户已经在其之前）。重置$alreadyscanned的值或使用数组来保留错误列表。

$alreadyscanned = [];
foreach ($json_data as $data){
    $barcodejson = $data['Barcode'];

    if($barcodejson == $barcode){
        $alreadyscanned[$barcodejson] = 'This user is already in your contacts';  
    } else { do something}
}

foreach($alreadyscanned as $barcode => $error) {
   var_dump($barcode. " :: "  . $error);
}

Answer 2

当你进入break部分时，考虑在循环中使用if：一旦找到重复内容，你不想继续：

if($barcodejson == $barcode){
    $alreadyscanned = 'This user is already in your contacts';  
    break;
} else { do something}

现在dosomething在这里可能是不受欢迎的（取决于它的作用）。您可能需要在单独的循环中执行此操作。像这样的东西：

$alreadyscanned= "";
foreach ($json_data as $data){
    $barcodejson = $data['Barcode'];

    if($barcodejson == $barcode){
        $alreadyscanned = 'This user is already in your contacts';  
        break;
    }
}
if ($alreadyscanned=="") {
    foreach ($json_data as $data){
        $barcodejson = $data['Barcode'];
       // do something
    }
}

Answer 3

缺少分号和东西会使得更难获得理想的结果。

这样的事情可能会帮助您获得所需的数据。基本上你可以通过print_r-json解码过程来检查解析的结果。

然后，您将获得每个条目的处理结果，并且再次作为测试，您可以打印生成的数组。

<?php
        //Enter your code here, enjoy!
$json = '[
{
    "FirstName": "lee",
    "LastName": "skelding",
    "Email": "mail.mail.com",
    "Barcode": "732580652913857773001",
    "Phone": "00000000",
    "Company": "SKELLATECH V3",
    "Position": "CEO"
},
{
    "FirstName": "Kenneth",
    "LastName": "Brandon",
    "Email": "mail.mail.com",
    "Barcode": "732559813913833509001",
    "Phone": null,
    "Company": null,
    "Position": null
},
{
    "FirstName": "lee",
    "LastName": "skelding",
    "Email": "mail.mail.com",
    "Barcode": "732580652913857773001",
    "Phone": "0000000000",
    "Company": "SKELLATECH V3",
    "Position": "CEO"
}]'
;

$barcode = '732580652913857773001'; //just an example this is set as a variable

$json_data = json_decode($json, true); 

print_r($json_data);


foreach ($json_data as $data){
    $barcodejson = $data['Barcode'];

    if($barcodejson == $barcode){
        $alreadyscanned[] = 'user ' . $data["Email"]  .' is already in your contacts';  
    } else { 
        $alreadyscanned[] = 'This user '.  $data["Email"] .'  is not in your contacts';  
    }
}

print_r($alreadyscanned);

Answer 4

您需要使用一个函数，以便在找到所需的条形码时使用return

function searchbarcode($json_data, $barcode)
{
   foreach($json_data as $data)
   {
      if ( $data['Barcode'] == $barcode )
         return true;
   }
   return false;
}
$barcode = '0000000' //just an example this is set as a variable
$json_data = json_decode($json,true);
if(searchbarcode($json_data, $barcode)){
    $alreadyscanned = 'This user is already in your contacts';  
} else { do something}